Currently, magnetic disk devices, solid-state storage drives (SSDs) and the like are used as storage devices. An SSD comprises, for example, stacked circuit boards and an enclosure accommodating these circuit boards. Memory devices such as NAND flash memories are mounted on each circuit board. Adjacent circuit boards are connected to each other via a connector.
In a structure in which three or more circuit boards are stacked, if a connector which connects the second circuit board to the third is offset in a plane direction of the circuit boards with respect to a connector which connects the first circuit board to the second, the circuit boards may tilt or bend while the connectors are mated, causing a mating error or connection error of the connectors.